Initial Enquiry:
ATZ Marine Technologies was approached by a large UK cruise operator to supply replacement white metal bearings for a complete shaft line at short notice.
Project Objectives:
Supply forward, centre and aft white metal bearings
Ensure fast delivery within a short time frame
Supply bearings with Lloyds Register inspection approval
Attend dock and liaise with yard and Lloyds to confirm machining dimensions and tolerances to match Sterntube.
Confirm post-machining final inspection results with customer and Lloyds sign off.
Supervise bearing installation and alignment checks.
Project Description:
Leading up to a planned docking the cruise vessel had suffered extensive aft seal damage and the consequential high volume of water ingress to the Sterntube on the starboard shaft line.
This had resulted in high-temperature alarms on the aft white metal bearing. It was suspected that the white metal bearing had been damaged as a result.
In consultation with ATZ, the customer mitigated risk by placing an order for a new aft white metal bearing to be installed at the upcoming planned docking. The order was placed with ATZ and was delivered in good time before the docking.
With guidance from Lloyds Register, further risk mitigation was put in place with the order of centre and forward bearings. This order was placed 3 days before the docking date and required a lead time of 8 calendar days. The lead time was successfully met by ATZ
After tail shaft withdrawal, it was found that only the aft bearing required replacement.
The aft bearing replacement was successfully executed under the supervision of ATZ.
Note that due to damage to the tail shaft in way of the aft bearing, the tail shaft itself was replaced with a spare.
The forward and centre bearings were put into storage as spares.
Conclusions:
ATZ successfully supplied:
- All required bearings within the required time frame
- Bearings meeting Lloyds Register inspection criteria
- Supervised the final machining, inspection and installation of the aft bearing to the approval of the customer and attending Lloyds surveyor.
The vessel docking schedule was not affected by the new bearing installation and sailed on time to meet her busy cruise schedule.